Various industrial or natural slurries are coarse, concentrated suspensions with a yield stress. Relevant practical methods are needed to determine the behaviour of such fluids. Here we provide a simple, theoretical approach to describe form of deposits remaining after free surface flow stoppage as a function of fluid characteristics. Thixotropy, inertial effects and sedimentation are neglected. It is demonstrated that the flow depth, as a function of the distance from the edge, can be predicted in any direction. Further analysis shows that there is a clear difference in the form of deposit edge between materials in which there is a grain-to-grain network of interaction and materials in which there is a network of colloidal interaction. These results provide a first order, practical, rheological and structural interpretation of current deposits of pastes, muds, slurries, fresh concrete or magmas.